Some new processor power settings in Win10 for Skylake+ CPUs

There are new hidden processor power settings in Windows10:

8baa4a8a-14c6-4451-8e8b-14bdbd197537 - Processor performance autonomous mode (Enable/Disable)
Specify whether processors should autonomously determine their target performance state.

36687f9e-e3a5-4dbf-b1dc-15eb381c6863 - Processor energy performance preference policy (Percent)
Specify how much processors should favor energy savings over performance when operating in autonomous mode.

cfeda3d0-7697-4566-a922-a9086cd49dfa - Processor autonomous activity window (Microseconds)
Specify the time period over which to observe processor utilization when operating in autonomous mode.

4e4450b3-6179-4e91-b8f1-5bb9938f81a1 - Processor duty cycling
Specify whether the processor may use duty cycling.

More on the subject - http://www.anandtech.com/show/9582/intel-skylake-mobile-desktop-launch-architecture-analysis/7

They all live in registry under the key 54533251-82be-4824-96c1-47b60b740d00 - Processor power settings. You can get and set them through powercfg.exe. But I prefer to unhide them - change their REG_DWORD value Attributes from 1 to 0 - and they will be shown in advanced power settings dialog under the "Processor power management" root node.
After the update to 1607 I noticed that Processor performance autonomous mode was enabled both in Perfomance and Balanced power plan. Article above says about Skylake CPUs and I have IvyBridge-E one. So I disabled this autonomous mode just in case. Guys with Skylake+ CPUs can check these settings on their rigs.

 

8baa4a8a-14c6-4451-8e8b-14bdbd197537 - Processor performance autonomous mode (Enable/Disable)
Specify whether processors should autonomously determine their target performance state.

Mine is also set to enable in that key.
I have IB 3570k

 

I suspect that if CPU doesn`t support feature then setting does nothing. But who knows - may be Intel and MS had a breakthrough implementing feature in Win10 and invented more optimal code even for older CPUs. I will check (later) whether this setting has impact on P-states on my rig.

 

I've published (and now corrected) the Skylake .REG to unhide *all* energy/performance options, including Duty Cycling at Bitsum.

I am also adding full Skylake support to ParkControl, be done with that shortly.

I am posting here because we will need a lot of feedback to determine the real-world effects of changing any of these options. While we can easily deduce the likely effect in many cases, in others the impact is less clear.

Sadly I can not post a link to the screenshot of the full power options, but all these are available for edit, not just autonomous mode ON/OFF. That is like a master control setting.

 

Those settings are not exposed by default. At least not yet. There is the possibility for them to be exposed in the future. It's quite possible that Intel/Microsoft don't want them to be used controlled though.

 

Well, there were a plenty of hidden power plan settings in Win7. When I discovered them I did unhide them and experimented with. There were immediate responses to the changing of those settings. In Win8 all those settings did continue to be hidden and also new ones appeared. Win10 continues the tradition and maintains all those setting hidden and also adds new ones. I assume that MS has a model of generic end user as kinda stupid guy who can not be trusted to play with power plan settings.

Edit:
Btw, I unearthed description of another hidden setting:
619b7505-003b-4e82-b7a6-4dd29c300971 - Latency sensitivity hint processor performance.
Specify the processor performance in response to latency sensitivity hints.

And according to this https://msdn.microsoft.com/en-us/library/windows/hardware/mt422951(v=vs.85).aspx :

Edit: Overall this resource https://msdn.microsoft.com/en-us/library/windows/hardware/mt608264(v=vs.85).aspx is quite interesting to browse.

 

We all know microsoft loves to hide settings. How else could they justify the different editions and costs of windows?

 

nice read gona enjoy tweaking this.

Btw. I use Process LASSO and it has a power profile called "Bitsum Highest Profile"
I noticed it disables all the power saving features of the cpu. I kinda liked the app so I bought it

 

@mbk1969

Thanks for sharing the info!

 

Here link to the article , with reg files at bottom (power options and pic's are mid way down).

https://bitsum.com/parkcontrol/

 

Welcome to G3D!

I have been using Process Lasso for some time now. Excellent product.

Isnt ParkControl part of that package?

 

Yes, there the free Park Control that comes with PL, but there Park control Pro with the added features (the link above has info on it).

What I can't comment is on Skylake support as I don't have that locally.

 

Thanks, Ed

 

I went to a Bitsum site and noticed that their description of CPU core parking differs from Microsoft` one:

You see: Bitsum describes core parking as C6 sleep state where Microsoft - as algorithm in OS kernel for leaving the core without work to let it dive into deeper idle state.

 

Btw, I just discovered command line method to unhide power plan settings:

So for processor settings:

Code:

powercfg  -attributes SUB_PROCESSOR power-setting-GUID [+ATTRIB_HIDE | -ATTRIB_HIDE]

I see that many pages in the Web state that to unhide the setting you should set REG_DWORD value Attributes to "2" (in registry), but after checking what powercfg -attributes does I see that it sets Attributes to "0".
There are settings in Win8+ with Attributes = "2" but I don`t know the meaning yet.

 

I can't speak for Jeremy but reading both boils down to saying roughly the same thing.
My guess is the one at Bitsum is a simplified one for the masses to understand, in a few small paragraphs.

 

none of these commands work for me, then again I still also using 1511 build, but they reg entries are there

 

I looked again, and for that key(8baa4a8a-14c6-4451-8e8b-14bdbd197537 - Processor performance autonomous mode (Enable/Disable)) the defaults for all power plans have these reg values with OS 1607.

"AcSettingIndex"=dword:00000000 (disabled)
"DcSettingIndex"=dword:00000000 (disabled)
"ProvAcSettingIndex"=dword:00000001 (enabled)
"ProvDcSettingIndex"=dword:00000001 (enabled)

If you enable it to show up in advanced power plan, it shows enabled

So I think if you have Skylake CPU it will read the "ProvxxSettingindex" value but if you have like me Ivy it reads and uses the XxSettingindex value, which is disabled.

That is just a guess through.

 

Yah i actual not even seing those so, I guess i need to update 1607 to see them? though I not gona do that, I will probably wait till the next major release


What is the full string I looking for?

 

I used the registry file from jcollake's site and got the options visible. They were already enabled except for duty cycle but SST still appears in red color in hwinfo64. I was taking it for granted that it is enabled because I read all we needed was skylake and above with windows 10 10586. Not sure what's going on.